Bass Guitar DIY preamp

[ColinS]

This is maybe a little out of the ordinary, but in my experience lots of techie types (myself included) are either closet bassists, or play in bands regularly.

My first audio DIY project was a G1176 limiting amp. MNATs board etc...works a treat, almost perfect at the first powering up (wired the input pot backwards so had no threshold control until I worked it out). It sounds fantastic inserted in the FX loop of my bass combo (Ashdown MAG 250)....I cannot recommend this compressor enough for bassists.

Anyway, I completed my 1176 about 6 or 8 months ago and I'm now looking towards a new project for the new year.

I am in the mood for a nice big sounding bass preamp. I am gravitating towards the G9 with all it's tubey goodness and having an instrument input already there will be quite straightforward to incorporate into my rig. 

Has anyone used or heard a G9 on bass guitar? What did you think?

I'm also open to suggestions towards other projects if anyone has any ideas for alternatives.

PS This is my first ever new topic on any forum anywhere, so be gentle please. I did have a look round to make sure I wasn't going over old ground, I didn't find anything, but I might not have been looking properly.

 

[Mbira]

The G9 is quite simply the shiznit on bass guitar.  G9 into G1176 has in the words of a very well respected engineer (and bass layer) in this town "given him the best bass sound he has ever recorded in the last 20 years". I am in the process of building him both so I can get mine back...Oh, go with the lundahls.

 

[ColinS]

I'm a bit of a traditionalist, so my 1176 has an electronically balanced input and a Lundahl output.

Lundahl stuff is fairly readily available in the UK so I'll probably go with them for a G9 if that's what I decide to make.

 

[EEMO1]

I remember matt liking the fetboy as a bass di?

 

[Emperor-TK]

The G9 is excellent on bass, but I prefer my home-brew Alembic F2-B.  I was also able to build an F2-B for much less money than the G9.  Somewhere on this board I posted sound clips comparing the G9 and F2-B.  It wasn't a fair shootout because I wasn't sure at the time what EQ settings on the F2-B give a theoretical response, so I dialed it to taste.  Still, it might be useful, give a search if you are interested.  If you go with a G9, don't discount OEP transformers.  I prefer them over Lundahls and almost never use my Lundahl channel.

-Chris

 

[Emperor-TK]

http://www.groupdiy.com/index.php?topic=28490.0

 

[clintrubber]

Hi,

As I understood it the G9 is a bit bass-shy, but that'll depend on the TXs used as well. And unless you play reggae it might fit the job actually.


I'm not sure what kind of add-on you want. Or how the G9 would fit in with your present rig. Do you want to replace the preamp of your Ashdown ? Then you might find that you're probably losing too much EQ-functionality; the G9 has a switchable HPF but no more than that.

In general it's easy to say what would be nice 'for bass', but that's fwiw (pub talk   )
When you really want to make it mean something then it's actually pretty hard to say what would be a nice complement for your present rig without knowing playing-style, kind of sound etc you're looking for. I'm mainly a bass-player myself and even with other bass-players that I know pretty well it can be a hit or miss w.r.t. gear recommendations. The basic stuff I'm using myself is pretty much unchanged over the last ten years but I only arrived at it by seeing what works for me by trying it myself.

Unfortunately not easy to cut corners there. So while there are sure valid starting points out there (You play with a pick ? Raw rock ? Then get this. You play fingerstyle & slap & want clean sound ? Then get that, & perhaps biamp  etc etc) , you still need to find your own combination of things that work for you, to get the sound that's inside your head (you obviously need to have a plan inside your head about what you want, otherwise the result will be random - which might be a nice surprise, but that route won't get you a recognizable & functional signature sound - assuming that that is what you want.)


Bottomline is:
does your rig really need anything ? Or are you just h*rny to add another DIY-gizmo ? If it's the latter and you just want to smell solder then that's fine as well of course  ;D
But it's not too easy to hint here what kind of thing would really suit your situation.

Bye,

 Peter

 

[skipwave]

I remember matt liking the fetboy as a bass di?

The Hamptone JFP (aka fetboy) is just unbelievably good for bass, IMHO. I use a single-stage JFP all the time for both bass and guitar. You can build one in 15 min on perfboard, just remember, the output capacitor is critical. On my someday-when-I-have-some-time to-do list; Compare the Sprague caps I'm using to Wima or Solen.

On the other hand, I've tried several of my tube mic pres as bass DI and they sound great in different ways. If that's what you're after, the Alembic has a tone stack and easy construction. Also, a far smaller value output cap, so you can afford to try different types and select your favorite.

EDIT: Talk about the Hamptone kit JFET and Tube pres as bass DI: http://messageboard.tapeop.com/viewtopic.php?t=59617

 

[Mr. Snoid]

How about a nice Alembic F-2B clone.  Nice tube warmth, real simple build, and there is a lot of stuff you can find just googling.  I think you can even find pcb art somewhere. It is really just like the input section of a Fender showman with slightly different tone control values.  Looks simple and cheap.  I'm dreaming of doing it and putting it through my orphaned McIntosh MC60 as a nice studio setup. Add a JBL D-140 and you're in bass heaven.


There's a schematic on Geofex: http://www.geofex.com/

Tod

 

[ColinS]

Thanks for all the replies. Some really useful points.

Emperor: Those samples you pointed me at do show up the difference between the Alembic and the G9. The Behringer sample doesn't sound any worse, just different.

I like both G9 and Alembic sounds, and will probably someday end up with both.

I've decided to go down the G9 route, for no other reason than the boards and information are far more available.

Clintrubber: Very true, every player is different and what works for one musician might not work for another. You're also right on the money with the being h*rny for a new DIY gizmo.... I really enjoyed my first project and like the feeling of accomplishment I gained from making something that actually works, and is pretty close to the mark as far as cloning a real top-drawer piece of kit.

My long term goal is to end up with a completely home-made bass rig, most of which would double as a vocal channel for recordings.

As you say replacing the Ashdown pre with a G9 loses me a lot of pretty nice EQ (and that amazing Ashdown Sub-octaver), it may be the case that my G9 becomes a fancy DI box in the short term untill I get around to building an EQ (and sub-octaver).

After that it'll be a power-amp and speaker cabinet......having done a bit of research I'm fairly sure the power amp will need to be solid state otherwise I'll end up with something weighing more than a bucket of neutrons.

Thanks again
Colin

 

[michal_k]

I also thought about making a DI for my double bass and I wondered if preamp section of ampeg b15 would be appropriate for that.

http://www.drtube.com/schematics/ampeg/b15n68-jp.gif

Should I do anything else except of putting a coupling cap before ext. amp out?

edit:

perhaps an SRPP stage(ecc82? 6sn7?) with an output transformer would be a good idea? what do you think?

 

[Arno]

A while ago I built a combination of an alembic/fender type with a srpp output with oep transformer (just like the G9)

Basically started with the same idea, B15 into srpp stage, but this worked best with my p-bass.

I just built everything on a wooden board as a prototype and put everything in a 1U case, point to point and have no oscillation or hum problems.

 

[michal_k]

A while ago I built a combination of an alembic/fender type with a srpp output with oep transformer (just like the G9)

Basically started with the same idea, B15 into srpp stage, but this worked best with my p-bass.

Ok, so no problems with bass amp pre to srpp stage? Or did you do any modifications? You don't have any soudclips af both b15 and alembic, do you?

 

[Denyle Guitars]

The B-15S has a preamp out so you could use that schematic instead. I use the line out on mine into an API preamp when I want something between a mic'd B-15 and a DI.

 

[stickjam]

How about a nice Alembic F-2B clone.  Nice tube warmth, real simple build, and there is a lot of stuff you can find just googling.  I think you can even find pcb art somewhere. It is really just like the input section of a Fender showman with slightly different tone control values.  Looks simple and cheap.  I'm dreaming of doing it and putting it through my orphaned McIntosh MC60 as a nice studio setup. Add a JBL D-140 and you're in bass heaven.


There's a schematic on Geofex: http://www.geofex.com/

Tod

The Alembic F-2B uses the same topology and EQ network as the Sadowsky bass preamp, FWIW.  (using jfets instead, and a fixed mid.)  I used to have a schemo for the Sadowsky but it vanished before I had a chance to build a dual-channel version for my Stick Bass. Maybe something like the F-2B is the ticket. 

I'm assuming the tube is probably an 12AT7 or 12AX7.  Any idea what the B+ runs at in the stock model?

-Bob